Seth Casteel's photos of about 75 dogs underwater are quite fun. Big dogs, little dogs and medium sized dogs are within the pages of this book.
Underwater Dogs: photographs of dogs underwater by Seth Casteel - Telegraph
There is a chihuahua named Bella, a Corgi mix called Bob, a Pug named Duncan, Jake a pit bull terrier mix, many Golden Retrievers, a border collier named Nevada and various other breeds of dogs.